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Céline Borg,1–3 Catherine Padovan,4,5 Catherine Thomas-Antérion,1,2 Céline Chanial,1 Anaïs Sanchez,1,5 Marion Godot,6 Roland Peyron,1,6,7 Odile De Parisot,5 Bernard Laurent1,6,71Neurology/Neuropsychology, Center Memory of Resources and Research Unit, North Saint-Etienne University Hospital Center, Avenue Albert Raimond, Saint-Priest-en-Jarez, France; 2Study of Cognitive Mechansims Laboratory, 3Psychology Unit, University Lumière of Lyon 2, Bron, France; 4Brain Dynamics and Cognition, Lyon Neuroscience Research Center and Vinatier Hospital Center, Bron, France; 5Germaine Revel Center, Dargoire, France; 6Pain Center, North Saint-Etienne University Hospital Center, Saint-Priest-en-Jarez, France; 7Central Integration of Pain, Lyon Neuroscience Research Center, Bron, FranceAbstract: In patients, the perception of pain intensity may be influenced by the subjective representation of their disease. Although both multiple sclerosis (MS) and fibromyalgia (FM) possibly include chronic pain, they seem to elicit different disease representations because of the difference in their respective etiology, the former presenting evidence of underlying lesions as opposed to the latter. Thus, we investigated whether patients with FM differed from patients with MS with respect to their perception of “own” pain as well as others' pain. In addition, the psychological concomitant factors associated with chronic pain were considered. Chronic pain patients with FM (n=13) or with MS (n=13) participated in this study. To assess specific pain-related features, they were contrasted with 12 other patients with MS but without chronic pain and 31 controls. A questionnaire describing imaginary painful situations showed that FM patients rated situations applied to themselves as less painful than did the controls. Additionally, pain intensity attributed to facial expressions was estimated as more intense in FM compared with the other groups of participants. There is good evidence that the mood and catastrophizing reactions expressed in FM differentially modulated the perception of pain according to whether it was their own pain or other's pain.Keywords: chronic pain, self and other's perspective, imaginary pain, facial expression

In spite of systematic investigations, the existence of a specific cortex that could encode for the intensities of somatosensory stimuli, including within nociceptive ranges, is still a matter of debate. The present consensus is that pain is expressed in a distributed network made of thalamus, SII, insula, ACC, and, less consistently, SI. Here we argument that there must be an entrance to this network. The common denominator to every functional imaging study is that the subjects can distinguish between noxious and non-noxious stimuli, or between two different intensities of noxious stimuli. This is associated with a consistent activation of the insula-SII cortices while activations in other brain areas may be missing or sub-significant. In other words, the operculo-insular cortex activations are the most robust pain-related activations across studies, whatever the manipulation of the pain components, except the discriminative one. Intra-cerebral recordings also pointed out this piece of cortex as being able to encode for pain intensity. As a last physiological argument, stimulating directly the brain with small intensities standardized electrical shocks elicited pain sensations selectively if the electrode was in the operculo-insular cortex. Human models of disease confirmed that epileptic discharges in the insular cortex can produce ictal pain. Insular epilepsy (or propagation of discharges to the insular cortex) is the only focal epilepsy to be possibly associated with painful symptoms. Finally, unique and focal lesions of the posterior operculo-insular cortices were able to remove (or at least to impair) thermosensory and nociceptive functions. Thus, the operculo-insular area can be presented as the only area in the brain to respond to the features of a primary thermosensory and nociceptive cortex. This area is likely to be the starting point of the nociceptive-related networks. Future investigations are necessary to determine how this "pain symphony" between these different brain areas is temporally orchestrated. Developments of new targets for functional neurosurgery could benefit of such localized and initiating processes, for instance focal neurostimulations. [ABSTRACT FROM AUTHOR]

Background: Amitriptyline has well-established efficacy in several chronic pain conditions. While optimal treatment for chronic neck pain (CNP) remains controversial, amitriptyline was not tested for CNP. We evaluated the effect of bedtime amitriptyline in the management of CNP.Methods: A total of 220 patients suffering from idiopathic CNP were randomized to receive either placebo pill (n = 108) or 5 mg of amitriptyline (n = 112) at bedtime for 2 months. Primary outcome measure was visual analog scale (VAS) for pain. Secondary outcome measures were neck pain disability index (NPDI), Bergen Insomnia Score (BIS) and Hospital Anxiety and Depression Scale (HAD), measured before and at the end of 2 months of treatment, with the percentage of patient satisfaction measured at the end of follow-up only.Results: Eight of 112 patients (7.14%) in the amitriptyline group withdrew from the study because of intolerance. Amitriptyline group showed significantly lower VAS scores than placebo group (3.34 ± 1.45 vs. 6.12 ± 0.92; p < 0.0001), which corresponds to a 53.06 ± 20.29% of improvement from baseline pain as compared to 14.41 ± 11.05%, respectively (p < 0.0001). Similar significant improvements were observed with lesser extents for secondary outcome measures: NPDI, BIS, HAD-A, HAD-D and percentage of patient satisfaction.Conclusion: Low-dose amitriptyline is effective for the management of idiopathic CNP with few side effects and high patients' satisfaction.Significance: This randomized controlled trial is the first to show the effectiveness and tolerance of a medication, low-dose amitriptyline, in managing idiopathic chronic neck pain and its related comorbidities. The optimal treatment of this condition was still controversial in the literature. It extends the indication of low-dose amitriptyline to another chronic pain condition. [ABSTRACT FROM AUTHOR]